NorthScale Membase Server Beta 3 is Here!

Frank Weigel
of
Couchbase
Published
August 30, 2010

I am excited to announce that NorthScale Membase Server 1.6 Beta3 is now available and ready for download. This beta release adds a lot of new functionality and reflects most of what you’ll find in the final product. Highlights include:

Windows support

Multi-tenancy – allows multiple buckets on a single cluster including bucket quotas

“Cluster Overview” as a new monitoring dashboard

And lots of small improvements and bug fixes, of course!

Let’s take a look at these features in a bit more detail: Windows support is by far one of the most frequently requested features, and we are very pleased to offer it with this beta release. Beta3 provides 32-bit Windows support, with 64-bit support on the way (Note: The 32bit binary runs just fine on Windows 64-bit but is subject to the 32-bit memory limits). The Windows version provides the same feature set as our Linux version.

Multi-tenancy is the mechanism for creating multiple buckets on one membase cluster. Each bucket represents a separate namespace, but more importantly it also provides a resource control mechanism on a per bucket basis, allowing buckets to have different behavior. For example if you have some data you consider very important, you may want to create a bucket with a replica count of 3; for other less crucial data, a replica count of 0 might make sense. This way you can decide how to divide the cluster resources to accommodate different requirements for different applications or different types. No more one size fits all! Bucket quotas are worth a bit more explanation. Each time you create a cluster, you set a fixed amount of memory that each server node in the cluster will contribute to the total cluster memory that buckets can consume. Once set, this value will be inherited by any server joining the cluster and cannot be changed. Hence, the total memory available for membase use in the cluster increases by this amount with each addition of server to the cluster. Similarly, each bucket defines a memory quota that sets the amount of memory it can use out of the cluster total memory. This quota does not change as you add servers to your cluster, but you can manually edit this on the “Manage Bucket” screen. In addition to the memory quota, there is also a disk quota associated with each bucket. In contrast to the memory quota, there is no fixed limit of disk space that each server brings to the cluster; all free disk space on the assigned storage path may be used. It is up to sysadmin to make sure that each node provides sufficient space to accommodate the data written (and you can track free disk space in the new Cluster Overview dashboard). Disk quotas are not yet enforced in Beta3, but you can already use it to monitor your bucket’s usage versus the quota. The Cluster Overview provides a single cluster overview dashboard, showing you the most crucial stats of your cluster in one place.

As you can see you get a single page to keep track of the memory and disk usage of all your buckets, as well as how many operations your cluster is performing. The “disk fetches per second” serves as a potential issue indicator. If you are seeing a lot of disk reads it means that the working set for at least one of your buckets does not fit into RAM alone anymore. Disk reads are much higher latency than memory reads, so should this happen you can use the Data Bucket monitor section to drill down and understand which bucket is encountering the issue. If you need to take action you can increase the bucket memory quota in the Manage Data Bucket section. Issue resolved! As you see we packed a lot of great new features into Beta3. But there is still more to come. You might be able to guess from the new bucket creation dialog that we have another bucket type in store, which will make multi-tenancy even more exciting – but for more on that you’ll have to check back later. Enjoy Beta3 and let us know how you are getting on with the new features!